Fabrication of bioactive glass scaffolds by stereolithography: Influence of particle size and surfactant concentration

For decades, bioactive glass (BAG) has been utilized as a competent bone substitute owing to its intrinsic properties, such as outstanding biocompatibility and bioresorbability. Stereolithography (SL) is an additive manufacturing technology used to produce highly accurate three-dimensional BAG-based bone substitutes. However, the preparation of BAG-based SL resin is always a challenge, especially because of the inevitable sedimentation of BAG particles. In this study, BAG particles with different sizes were prepared by dry grinding (BAGdry, greater particle size) and wet grinding (BAGwet, finer particle size). Then, BAGdry or BAGwet SL resins with various amounts of surfactant were analyzed. The sedimentation rate for BAG powder increased with increasing particle size but decreased with increasing amounts of surfactant added to the resin. BAGwet SL resins had a longer shelf life, so printing could still be finished after 14 days, whereas BAGdry SL resins were no longer useable after 5 days. However, the BAG particle size did not affect the printing accuracy or scaffold strength. According to our results, BAG-based SL resin fabricated with BAGwet (particle size <1.6 μm) and 5 wt% surfactant exhibited better resistance to sedimentation.